/**
 * @file
 * DHCP protocol definitions
 */

/*
 * Copyright (c) 2001-2004 Leon Woestenberg <leon.woestenberg@gmx.net>
 * Copyright (c) 2001-2004 Axon Digital Design B.V., The Netherlands.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * This file is part of the lwIP TCP/IP stack.
 *
 * Author: Leon Woestenberg <leon.woestenberg@gmx.net>
 *
 */
#ifndef LWIP_HDR_PROT_DHCP_H
#define LWIP_HDR_PROT_DHCP_H

#include "lwip/opt.h"
#include "lwip/arch.h"
#include "lwip/prot/ip4.h"

#ifdef __cplusplus
extern "C"
{
#endif

    /* DHCP message item offsets and length */
#define DHCP_CHADDR_LEN  16U
#define DHCP_SNAME_OFS   44U
#define DHCP_SNAME_LEN   64U
#define DHCP_FILE_OFS    108U
#define DHCP_FILE_LEN    128U
#define DHCP_MSG_LEN     236U
#define DHCP_OPTIONS_OFS (DHCP_MSG_LEN + 4U) /* 4 byte: cookie */

#ifdef PACK_STRUCT_USE_INCLUDES
#include "arch/bpstruct.h"
#endif
    PACK_STRUCT_BEGIN
    /** minimum set of fields of any DHCP message */
    struct dhcp_msg
    {
        PACK_STRUCT_FLD_8(u8_t op);
        PACK_STRUCT_FLD_8(u8_t htype);
        PACK_STRUCT_FLD_8(u8_t hlen);
        PACK_STRUCT_FLD_8(u8_t hops);
        PACK_STRUCT_FIELD(u32_t xid);
        PACK_STRUCT_FIELD(u16_t secs);
        PACK_STRUCT_FIELD(u16_t flags);
        PACK_STRUCT_FLD_S(ip4_addr_p_t ciaddr);
        PACK_STRUCT_FLD_S(ip4_addr_p_t yiaddr);
        PACK_STRUCT_FLD_S(ip4_addr_p_t siaddr);
        PACK_STRUCT_FLD_S(ip4_addr_p_t giaddr);
        PACK_STRUCT_FLD_8(u8_t chaddr[DHCP_CHADDR_LEN]);
        PACK_STRUCT_FLD_8(u8_t sname[DHCP_SNAME_LEN]);
        PACK_STRUCT_FLD_8(u8_t file[DHCP_FILE_LEN]);
        PACK_STRUCT_FIELD(u32_t cookie);
#define DHCP_MIN_OPTIONS_LEN 68U
/** make sure user does not configure this too small */
#if ((defined(DHCP_OPTIONS_LEN)) && (DHCP_OPTIONS_LEN < DHCP_MIN_OPTIONS_LEN))
#undef DHCP_OPTIONS_LEN
#endif
/** allow this to be configured in lwipopts.h, but not too small */
#if (!defined(DHCP_OPTIONS_LEN))
/** set this to be sufficient for your options in outgoing DHCP msgs */
#define DHCP_OPTIONS_LEN DHCP_MIN_OPTIONS_LEN
#endif
        PACK_STRUCT_FLD_8(u8_t options[DHCP_OPTIONS_LEN]);
    } PACK_STRUCT_STRUCT;
    PACK_STRUCT_END
#ifdef PACK_STRUCT_USE_INCLUDES
#include "arch/epstruct.h"
#endif

    /* DHCP client states */
    typedef enum
    {
        DHCP_STATE_OFF = 0,
        DHCP_STATE_REQUESTING = 1,
        DHCP_STATE_INIT = 2,
        DHCP_STATE_REBOOTING = 3,
        DHCP_STATE_REBINDING = 4,
        DHCP_STATE_RENEWING = 5,
        DHCP_STATE_SELECTING = 6,
        DHCP_STATE_INFORMING = 7,
        DHCP_STATE_CHECKING = 8,
        DHCP_STATE_PERMANENT = 9, /* not yet implemented */
        DHCP_STATE_BOUND = 10,
        DHCP_STATE_RELEASING = 11, /* not yet implemented */
        DHCP_STATE_BACKING_OFF = 12
    } dhcp_state_enum_t;

/* DHCP op codes */
#define DHCP_BOOTREQUEST 1
#define DHCP_BOOTREPLY   2

/* DHCP message types */
#define DHCP_DISCOVER     1
#define DHCP_OFFER        2
#define DHCP_REQUEST      3
#define DHCP_DECLINE      4
#define DHCP_ACK          5
#define DHCP_NAK          6
#define DHCP_RELEASE      7
#define DHCP_INFORM       8

#define DHCP_MAGIC_COOKIE 0x63825363UL

/* This is a list of options for BOOTP and DHCP, see RFC 2132 for descriptions */

/* BootP options */
#define DHCP_OPTION_PAD         0
#define DHCP_OPTION_SUBNET_MASK 1 /* RFC 2132 3.3 */
#define DHCP_OPTION_ROUTER      3
#define DHCP_OPTION_DNS_SERVER  6
#define DHCP_OPTION_HOSTNAME    12
#define DHCP_OPTION_IP_TTL      23
#define DHCP_OPTION_MTU         26
#define DHCP_OPTION_BROADCAST   28
#define DHCP_OPTION_TCP_TTL     37
#define DHCP_OPTION_NTP         42
#define DHCP_OPTION_END         255

/* DHCP options */
#define DHCP_OPTION_REQUESTED_IP           50 /* RFC 2132 9.1, requested IP address */
#define DHCP_OPTION_LEASE_TIME             51 /* RFC 2132 9.2, time in seconds, in 4 bytes */
#define DHCP_OPTION_OVERLOAD               52 /* RFC2132 9.3, use file and/or sname field for options */

#define DHCP_OPTION_MESSAGE_TYPE           53 /* RFC 2132 9.6, important for DHCP */
#define DHCP_OPTION_MESSAGE_TYPE_LEN       1

#define DHCP_OPTION_SERVER_ID              54 /* RFC 2132 9.7, server IP address */
#define DHCP_OPTION_PARAMETER_REQUEST_LIST 55 /* RFC 2132 9.8, requested option types */

#define DHCP_OPTION_MAX_MSG_SIZE           57 /* RFC 2132 9.10, message size accepted >= 576 */
#define DHCP_OPTION_MAX_MSG_SIZE_LEN       2

#define DHCP_OPTION_T1                     58 /* T1 renewal time */
#define DHCP_OPTION_T2                     59 /* T2 rebinding time */
#define DHCP_OPTION_US                     60
#define DHCP_OPTION_CLIENT_ID              61
#define DHCP_OPTION_TFTP_SERVERNAME        66
#define DHCP_OPTION_BOOTFILE               67

/* possible combinations of overloading the file and sname fields with options */
#define DHCP_OVERLOAD_NONE       0
#define DHCP_OVERLOAD_FILE       1
#define DHCP_OVERLOAD_SNAME      2
#define DHCP_OVERLOAD_SNAME_FILE 3

#ifdef __cplusplus
}
#endif

#endif /* LWIP_HDR_PROT_DHCP_H */
